ELM elimination with Li powder injection in EAST discharges using the tungsten upper divertor

Maingi, R. ; Hu, J. S.; Sun, Z.; Tritz, K.; Zuo, G. Z.; Xu, W.; Huang, M.; Meng, X. C.; Canik, J. M.; Diallo, A. ; Lunsford, R. ; Mansfield, D. K. ; Osborne, T. H.; Gong, X. Z.; Wang, Y. F. ; Li, Y. Y.
Issue date: 2017
Rights:
Creative Commons Attribution 4.0 International (CC BY)
Cite as:
Maingi, R., Hu, J. S., Sun, Z., Tritz, K., Zuo, G. Z., Xu, W., Huang, M., Meng, X. C., Canik, J. M., Diallo, A., Lunsford, R., Mansfield, D. K., Osborne, T. H., Gong, X. Z., Wang, Y. F., & Li, Y. Y. (2017). ELM elimination with Li powder injection in EAST discharges using the tungsten upper divertor [Data set]. Princeton Plasma Physics Laboratory, Princeton University. https://doi.org/10.11578/1562064
@electronic{maingi_r_2017,
  author      = {Maingi, R. and
                Hu, J. S. and
                Sun, Z. and
                Tritz, K. and
                Zuo, G. Z. and
                Xu, W. and
                Huang, M. and
                Meng, X. C. and
                Canik, J. M. and
                Diallo, A. and
                Lunsford, R. and
                Mansfield, D. K. and
                Osborne, T. H. and
                Gong, X. Z. and
                Wang, Y. F. and
                Li, Y. Y.},
  title       = {{ELM elimination with Li powder injection
                 in EAST discharges using the tungsten u
                pper divertor}},
  publisher   = {{Princeton Plasma Physics Laboratory, Pri
                nceton University}},
  year        = 2017,
  url         = {https://doi.org/10.11578/1562064}
}
Description:

We report the first successful use of lithium (Li) to eliminate edge-localized modes (ELMs) with tungsten divertor plasma-facing components in the EAST device. Li powder injected into the scrape-off layer of the tungsten upper divertor successfully eliminated ELMs for 3-5 sec in EAST. The ELM elimination became progressively more effective in consecutive discharges at constant lithium delivery rates, and the divertor D-alpha baseline emission was reduced, both signatures of improved wall conditioning. A modest decrease in stored energy and normalized energy confinement was also observed, but the confinement relative to H98 remained well above 1, extending the previous ELM elimination results via Li injection into the lower carbon divertor in EAST [J.S. Hu et al., Phys. Rev. Lett. 114 (2015) 055001]. These results can be compared with recent observations with lithium pellets in ASDEX-Upgrade that failed to mitigate ELMs [P.T. Lang et al., Nucl. Fusion 57 (2017) 016030], highlighting one comparative advantage of continuous powder injection for real-time ELM elimination.

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